Expansion-bolt.



No. 68I,8I7. Patented Sept. 3, 190|. C. H. SMITH.

EXPANSION BOLT.

(Applicfiton led Feb. 28, 1901.5

.No Model.)

FIG. t

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F168. E69. Fui/0.

WITNESSES. ffm

UNTTED STATES PATENT QFFICE.

CHARLES H. SMITH, OF PITTSBURG, PENNSYLVANIA.

EXPANSION-BOLT.

SPECIFICATION forming part of Letters Patent N o. 681,817, dated September 3, 1901. Application fled February 28,1901. Serial No.481495. (No model.)

To all whom it may concern:

Be it known that I, CHARLEs H. SMITH,a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Expansion- Bolts; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to expansion-bolts, its object being to provide a simple form of bolt of this character which is adapted for use in masonry, brick, or wood with equal success, and one which when properly secured in place will form a strong and durable support for the object to be suspended therefrom, while at the same time it may be readily removed without difculty and without injury to any of the parts composing the same.

To these ends my invention comprises, generally stated, in conjunction with a bolt, a Wedge threaded internally and engaged by said bolt, said wedge having two of its sides tapering and the remaining sides parallel, t0- gether with a twopart shell inclosing said wedge and adapted by the action of said Wedge to be forced out equally for its entire length into the walls of the opening made to receive the bolt, the faces of said shell being roughened or indented so as to obtain a secure hold on the material in which the bolt is inserted.

To enable others skilled in the art to make and use myinvention, I will describe the same more fully, referring to the accompanying drawings, in which- Figure l is a View of my improved expansion-bolt before the expansion takes place. Fig. 2 is a vertical sectional View showing the bolt expanded. Fig. 3 is an inverted plan View. Fig. 4 is a top plan view. Fig. 5 isa perspective view of one-half of the shell. Fig. 6 is a plan View of the two parts of the shell. Fig. 7 is a perspective View of the conical inner Wedge. Figs. S, E), and l0 show bolts of different forms.

Like numerals refer to like parts in each of the figures.

In the drawings, the numeral 2 designates the wedge, which has the two tapering or sloping sides 3, which are curved and of the same radius throughout their length, but with different centers. The wedge 2 has also the two parallel or straight sides 4, as clearly illustrated. The interior of the wedge 2 is threaded, so as to receive the bolt 5. This bolt 5 is threaded for a portion of its length,

as at 6, atits inner end and again at its outer end, as at 7, the intermediate portion 8 remaining smooth. The threaded portion 7 is for the attachment of the object to be supportedby the bolt. The interior of the Wedge 2 is slightly cutaway, as at 9, to permit of the clearance of the Wedge when it is drawn up tothe smooth or Unthreaded portion S of the bolt.

Surrounding the wedge 2 is the twopart shell, composed of the portions ll and l2, which are so shaped internally as to conform to the tapering and parallel sides 3 and 4 of the wedge 2 and so as to be in contact with the tapering sides of said wedge at all points throughout the length of said sides and in all positions of the wedge.

The outer faces of the portions ll and 12 of the shell are preferably circular and are ribbed or indented in such a Way as to form sharp edges adapted to grip or bite into the material in which the bolt is inserted. The shells illustrated have the circular ribs l2 arranged at intervals for the entire length thereof, the edges of said ribs being sharpened to permit of their forcing their way more readily intothe surrounding material. By having the ribs formed with beveled edges and the larger diameter toward the outer end it is apparent that when said shells are expanded any force exerted to withdraw said shells will only tend to make them take a stronger hold on the material. It is manifest that projections of any suitable form or character may be formed on the shell to eifect'this result. A plate 13 is interposed between the nut 14 on the bolt 5 and the outer ends of the shell, the purpose of said plate being to prevent any outward movement on the part ofthe shell when the wedge is expanded, as will more fully hereinafter appear. In Figs. 9 and l0 I have illustrated other forms of bolt in which the hook 18 or the eye 19 are formed on the outer ends of the bolts, so as to form convenient means for attaching the object to be suspended therefrom. The shoulder 2O serves the purpose of the nut.

When my improved expansion-bolt is in use, its operation is as follows: The parts are IOO assembled as shown in Fig. 1, and in this form the bolt is inserted into the recess 15 in the masonry, brick, wood, or other material and the nut 14 on the bolt is drawn up until it reaches the shoulder 1G of the smooth portion S of the bolt, whereupon it is apparent that any further turning ot' said nut will result in the turning of the bolt also. This rotationrof lthe bolt will cause the non-rotary wedge 2 to move outward, and as a result of this outward movement of the wedge the cylindrical portions 11 and 12 of the shell will move out laterally into contact with the walls of the recess in which the bolt has been inserted. This movement of the shells will continue as long as the wedge advances, and as the pressureplate 13 bears against the surrounding portion of the material the effect of the rotation of the bolt will be to force said plate into contact with the material and withdraw the wedge, so that the only possible movement which the cylindrical portions 11 12 of the shell can take is in a lateral or horizout-al direction. As a consequence all the wedging force exerted by the wedge acts on the shell in only one direction, and consequently said shell takes a firmer and more positive hold on the Walls of the material. The teeth of the shell grip and bite into the material, and the position of the shell is thereby further strengthened against withdrawal. The wedge may be withdrawn unvtil its outer end approaches the outer end of the shell, for which reason the wedge preferably approximates in length the length of the shell. 1n order that the smooth or unthreaded portion 8 of the bolt may not interfere with its progress, said wedge is cut away, as at 9, as before stated. It is apparent that, it' desired, the bolt may be made with the head A or nut 17 formed integral therewith, as shown in Fig. 8. n

By the above construction I obtain an expansion-bolt in which the tapering .curved sides of the wedge are adapted to be in contact throughout their length with, the inner faces ofthe shell in all positions of the wedge, so that the shell is forced out by an equal pressure at all points throughout its length when the bolt is turned, and for this reason there are no open spaces between the walls of the shell and the wedge to form weak points, asis the case when conical blocks are used; but the expansion-bolt consists practically of a solid mass of metal of equal strength throughout and presenting no points of weakness, so that all danger of broken or contorted shells is practically eliminated. Owing to the form of the wedge rotation on the part of same is impossible and there is no undue strain brought to bear upon said wedge when the bolt is turned. The shell being formed in two parts permits of the shells being expanded in but one direction and all the teeth ol' said shell bear with equal pressure against the walls of the recess.

These expansion-bolts are used for many different purposes and my improved bolt can be set in place and expanded without the necessity of attaching the object to be supported thereby at the same time, as said object may be attached to the bolt at any time after the bolt is in position. To remove the bolt, it is only necessary to unscrew the bolt 5 and by tapping the outer end of the bolt force in the wedge sufficiently to allow the shells to loosen, after which they may be readily removed. This may necessitate the drilling or boring of the hole somewhat deeper than the length of the bolt; but this is a matter of no consequence.

What I claim as my invention, and desire to secure by Letters Patent, is

1. An expansion-bolt comprising a wedgeblock having opposite tapering and parallel sides, a shell composed of independent halves surrounding said wedge-block and having inner faces conforming to said wedge-block and bearing against the same throughout the length of the latter, and abolt engaging said wedge-block, whereby as said bolt is turned the shell is expanded with equal pressure throughout its length.

2. An expansion-bolt comprising a wedgeblock having opposite tapering and parallel sides, the tapering sides being curved, a shell composed of independent halves surrounding said wedge-block and having inner faces con-y forming to said wedge block and bearing against the same throughout the length of the latter, and a bolt engaging said wedgeblock, whereby as said bolt is turned the shell is expanded with equal pressure throughout its length.

3. An expansion-bolt comprising a wedgea block having opposite tapering and parallel sides, a shell composed of independent halves surrounding said wedge-block and having their inner faces conforming to said wedgeblock and bearing against the same throughout the length of the latter, and a bolt en gaging said wedge-block, said wedge-block reaching, or nearly so, the outer ends of said shell and extending back beyond the mid-portion of said shell, or approximately the length of said shell, when the bolt is expanded.

4. An expansion-bolt comprising a wedgeblock having opposite tapering and parallel sides, a shell composed of independent halves surrounding said wedge-,block and having their inner faces conforming to said wedgeblock and bearing against the same throughout the length of the latter, the outer faces of said shell having projections or indentations, and a bolt engaging said Wedge-block, whereby as said bolt is turned the shell is expanded with equal pressure throughout its length.

5. An expansion-bolt comprising a wedgeblock having opposite tapering and parallel sides, a circular shell composed of independent halves surrounding said wedge-block and having their inner faces conforming to said wedge-block and bearing against the same throughout the length of the latter, the outer tog faces of said shell having circular ribs at suitable intervals throughout its length, and a bolt engaging said Wedge-block, whereby as said bolt is turned the shell is expanded with equal pressure throughout its length.

G. An expansion-bolt comprising a Wedgebloek having opposite tapering and parallel sides, a circular shell composed of independent halves surrounding said Wedge-block and having their inner faces conforming to said Wedge-block and bearing against the same throughout the length of the latter, the outer l l l faces of said shell having circular ribs at suitable intervals throughout its length, said ribs being beveled on their innersides, and a bolt 15 engaging said Wedge-block, whereby as said bolt is turned the shell is expanded with equal pressure throughout its length.

In testimony whereof I, the said CHARLES H. SMlTH, have hereunto set my hand.

CHARLES H. SMITH. Witnesses:

JOHN GAFFNEY, A. R. BEAM. 

